<div class="demo">
  <div class="demo-space">
    <span nz-icon nzType="smile" nzTheme="twotone"></span>
    <span nz-icon nzType="heart" nzTheme="twotone" nzTwotoneColor="red"></span>
    <span
      nz-icon
      nzType="check-circle"
      nzTheme="twotone"
      nzTwotoneColor="#52c41a"
    ></span>
  </div>
</div>
